Limit _XOPEN_SOURCE to Linux.

POSIX feature macros are a mess. Reportedly, FreeBSD also breaks with
_XOPEN_SOURCE, so try leaving it unset by default.

Update-Note: It's possible this will break yet another obscure UNIX.
Hopefully we can eventually find a combination that works?

Bug: 471
Change-Id: I103f8093110d343789b9c5a22eb056ab78d9cd14
Reviewed-by: Adam Langley <>
1 file changed
tree: c312671f043fbd235507465515d26048267932aa
  1. .github/
  2. crypto/
  3. decrepit/
  4. fuzz/
  5. include/
  6. rust/
  7. ssl/
  8. third_party/
  9. tool/
  10. util/
  11. .clang-format
  12. .gitignore
  16. CMakeLists.txt
  25. codereview.settings
  26. go.mod
  27. go.sum
  28. sources.cmake


BoringSSL is a fork of OpenSSL that is designed to meet Google's needs.

Although BoringSSL is an open source project, it is not intended for general use, as OpenSSL is. We don't recommend that third parties depend upon it. Doing so is likely to be frustrating because there are no guarantees of API or ABI stability.

Programs ship their own copies of BoringSSL when they use it and we update everything as needed when deciding to make API changes. This allows us to mostly avoid compromises in the name of compatibility. It works for us, but it may not work for you.

BoringSSL arose because Google used OpenSSL for many years in various ways and, over time, built up a large number of patches that were maintained while tracking upstream OpenSSL. As Google's product portfolio became more complex, more copies of OpenSSL sprung up and the effort involved in maintaining all these patches in multiple places was growing steadily.

Currently BoringSSL is the SSL library in Chrome/Chromium, Android (but it's not part of the NDK) and a number of other apps/programs.

Project links:

There are other files in this directory which might be helpful: